DESC:FIELD OF THE INVENTION
The present invention relates to a fungicidal composition. More particularly, the present invention relates to a synergistic fungicidal composition comprising Chlorothalonil and Thiophanate methyl.
BACKGROUND OF THE INVENTION
The control of plant diseases caused by fungal plant pathogens is extremely important in achieving high crop efficiency. Plant disease damage to ornamental, vegetable, field, cereal and fruit crops can cause significant reduction in productivity and thereby result in increased costs to the consumer. In addition to often being highly destructive, plant diseases can be difficult to control and may develop resistance to commercial fungicides. Combinations of fungicides are often used to facilitate disease control, to broaden spectrum of control and to retard resistance development. The advantages of particular fungicide combinations are recognized in the art to vary, depending on such factors as the particular plant species and plant disease to be treated, and whether the plants are treated before or after infection with the fungal plant pathogen. Accordingly new advantageous combinations are needed to provide a variety of options to best satisfy particular plant disease control needs. Furthermore, certain rare combinations of fungicides demonstrate a greater-than-additive (i.e. synergistic) effect to provide commercially important levels of plant disease control.
When two or more substances in combination demonstrate unexpectedly high biologically activity, for example fungicidal activity, the resultant phenomenon may be referred to as synergism. The reason or mechanism for the synergy may not be always known, and may differ with different combinations, but the effect can always be observed experimentally. The term ‘synergism’ or ‘synergy’ hereinafter refers to a cooperative action encountered in a combination of two or more biologically active components in which the combined activity of the two or more components exceeds the sum of the activity of each component alone.
Chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile) is a polychlorinated aromatic compound mainly used as a broad spectrum, nonsystemic fungicide, with other uses as a wood protectant, pesticide, acaricide, and to control mould, mildew, bacteria, and algae. Chlorothalonil-containing products are sold under the names Bravo, Echo, and Daconil. It was first registered for use in the US in 1966. In 1997, the most recent year for which data are available, it was the third most used fungicide in the US, behind only sulfur and copper, with some 12 million lb used in agriculture alone that year. The EPA estimates, on average, almost 15 million lb were used annually from 1990 to 1996, including the non-agricultural uses. Its structure formula is represented as follows:

The standard composition of Chlorothalonil available in the art is 75 percent wettable powder. However, there are many disadvantages associated with the use of these. For example, disadvantages associated with powder composition.
WO 2014060880 A1 discloses fungicidal composition comprising Mancozeb and Chlorothalonil in a ratio of 5: 1 as water dispersible granules for controlling foliar late blight and alternaria leaf spot.
The article titled "Fungicides to Control Early and Late Blight on Russet Norkotah Potatoes" Steven R. James and Frederick J. Crowe, discloses an experiment to evaluate the efficacy of selected fungicides on early and late blight control on Russet Norkotah potatoes. The article discloses Dithane+Bravo WS at the rate of 3.20pt/a + 1.50 pt/a (Dithane-mancozeb, Bravo-Chlorothalonil) and Dithane/Bravo 3.2pt/a applied individually. It was observed that there were no significant differences (p<5%) among the fungicide treatments except for the week of August 30 when more early blight infected plants were observed in the Dithane/Bravo (mancozeb/chlorothalonil) when applied individually. Therefore, although the combination of mancozeb with chlorothalonil is known, the precise concentrations at which the combination shows proper synergistic effect in treating fungal infection is not known.
Even more preferred mixtures according to the invention include: difenoconazole and chlorothalonil; propiconazole and chlorothalonil; azoxystrobin and chlorothalonil; triticonazole and chlorothalonil; difenoconazole and propiconazole and chlorothalonil; propiconazole and fludioxonil and chlorothalonil; difenoconazole and benzovindiflupyr (benzovindiflupyr is 3-difluoromethyl-1 -methyl-1 H-pyrazole- 4-carboxylic acid (9-dichloromethylene-1 ,2,3,4-tetrahydro-1 ,4-methano- naphthalen-5-yl)-amide and its microbicidal properties are described for example in WO 2007/048556) and chlorothalonil. Particularly preferred mixtures include difenoconazole and chlorothalonil, propiconazole and chlorothalonil, difenoconazole and propiconazole and chlorothalonil.
Thiophanate methyl, is a systemic fungicide with protective and curative action and is used against a wide range of fungal pathogens in post-harvest treatment and seed-treatment. It is the generic name for dimethyl-4,4'-(o-phenylene)bis(3-thioallophanate) which may be represented by the following formula:

Thiophanate-methyl is a carbendazim precursor and effective against wide range of fungal diseases in cereals, fruits, vegetables, fiber and ornamental crops, including rust, rot, anthracnose, eyespot, scab, leaf spot, mildew, Monilia spp., club root, dollar spot, Botrytis, Sclerotinia spp. etc.
The article titled "Intensity of anthracnose on three wintercreeper euonymus cultivars as influenced by fungicide program" Janet C. Cole, Stephanie L. Schupbach, and Kenneth E. Conway, discloses an experiment to evaluate the efficacy of selected fungicides on anthracnose on three winter euonymus cultivars. The article discloses Thiophanate methyl + propiconazole at the rate of 1500 mg a.i./l + 75 g a.i./l, Thiophanate methyl + propiconazole at the rate of 600 mg a.i./l + 75 g a.i./l, Thiophanate methyl + Thiophanate methyl at the rate of 1500 mg a.i./l + 600 mg a.i./l mg a.i./l, and Propiconazole at the rate of 37.5 gm a.i./l & 75 gm a.i./l, Thiophanate Methyl at the rate of 750 mg a.i./l & 1500 mg a.i./l and Thiophanate methyl at the rate of 300 mg a.i./l & 600 mg a.i./l applied individually. The fungicides were applied at the regular intervals. It was observed that there were no significant differences (p<5%) among the fungicide treatments except for the last observation on September 18 when more anthracnose disease rating were observed in the Thiophanate Methyl/ propiconazole/thiophanate methyl when applied individually. Therefore, although combinations of thiophanate methyl with different fungicides including azoles are known in the art, there is a need to investigate its combinations with other fungicides as all the known combinations do not afford effective control against a broad spectrum of diseases in different crops.
Hence, there is still a need for new compositions which are broad spectrum, having higher fungicidal activity and less toxicity. Accordingly, there is a need for novel, stable and safe combinations comprising thiophane methyl along with a synergistic component.
SUMMARY OF THE INVENTION
In accordance with an embodiment of the invention, there is provided a synergistic fungicidal composition, comprising Chlorothalonil, Thiophanate methyl and additives.
The synergistic fungicidal composition comprises Chlorothalonil and Thiophanate methyl in a mass ratio in the range from 0.75:1 to 1.33:1, preferably 1:1.
Further, Chlorothalonil is present in an amount in the range from 30 to 40% and Thiophanate methyl is present in an amount in the range from 30 to 40%.
The synergistic fungicidal composition may be in the form of a wettable powder (WP), a dry flowable (DF), a wettable solid (WS), a water dispersible granule (WG), or a suspension concentrate (SC).
Furthermore, the synergistic fungicidal composition, comprises additives selected from the group consisting of a dispersing agent, a wetting agent, a defoamer or an anti-foaming agent, a disintegration agent, a filler and combinations thereof, and wherein the composition is in the form of a water dispersible granule (WG).
The synergistic fungicidal composition comprises dispersing agent in an amount of 1 to 10%, the wetting agent in an amount of 2 to 3%, the defoamer or anti-foaming agent in an amount of 0.01 to 0.50%, and the disintegration agent in an amount of 0.10-5.00%.
In accordance with another embodiment of the invention, the synergistic fungicidal composition is non-phytotoxic and has good stability, wettability, suspensibility and dispersibility.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a flowchart for preparing synergistic fungicidal composition comprising Chlorothalonil and Thiophanate methyl in the form of water dispersible granules (WG) using spray dryer technique.
Figure 2 is a flowchart for preparing synergistic fungicidal composition comprising Chlorothalonil and Thiophanate methyl in the form of water dispersible granules (WG) using extruder technique.
DETAILED DESCRIPTION OF THE INVENTION
The invention according to its various aspects is particularly pointed out and distinctly claimed in the appended claims read in view of this specification and appropriate equivalents.
It is to be noted, as used in the specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a composition containing “a compound includes a mixture of two or more compounds. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. The expression of various quantities in the terms of “% w/w” and “%” means the percentage by weight, relative to the weight of the total composition unless otherwise specified.
As used herein DF formulation, WG formulation, WP formulation, SC formulation, WS formulation are the international denominations adopted by the FAO (Food and Agriculture Organization of the United Nations) to designate dry flowable, water dispersible granule, wettable powder, suspension concentrate, and wettable solid respectively.
The term "agrochemically effective amount" is that quantity of active agent, applied in any amount which will provide the required control of pest and diseases. The particular amount is dependent upon many factors including, for example, the crop, pest and disease sought to be controlled and environmental conditions. The selection of the proper quantity of active agent to be applied, however, is within the expertise of one skilled in the art.
Compositions comprising a single fungicidally active component suffer from numerous drawbacks such as development of resistant species, requirement of high amount and concentration of the active ingredient, environmental damage, seepage of the active component into ground water, phyto-toxicity and harmful effects on the health of animals and humans.
Accordingly, the inventors of the present invention have formulated a synergistic fungicidal composition, comprising: Chlorothalonil; Thiophanate methyl; and additives; wherein Chlorothalonil and Thiophanate methyl are present in a mass ratio in the range from 0.75:1 to 1.33:1, preferably 1:1.
The synergistic fungicidal composition of the present invention may be formulated as suspension concentrate (SC), a water dispersible granule (WG), a wettable powder (WP). a dry flowable (DF), or a wettable solid (WS).
Preferably, the synergistic fungicidal composition is in the form of water dispersible granules (WG) and the additives are selected from the group consisting of a dispersing agent, a wetting agent, a defoamer or anti-foaming agent, a disintegration agent, a filler and combinations thereof. The term “Water dispersible granules” refers to granules that are obtained by blending and agglomerating a ground solid active ingredient together with excipients.
The synergistic fungicidal composition preferably contains Chlorothalonil in an amount in the range from 30 to 40% and Thiophanate methyl in an amount in the range from 30 to 40%.
It is generally observed that solid particles in a liquid undergo spontaneous aggregation to form lumps. Hence it is recommended to add a dispersant or a dispersing agent which prevents aggregation of solid particles and keeps them suspended in the fluid. Accordingly, the composition of the present invention preferably contains an emulsifier cum dispersant or a dispersing agent such as sodium salt of naphthalene sulfonate condensate; sulfonated aromatic polymer sodium salt; sodium polycarboxylate; ethanesulfonic acid(2-[methyl[(9Z)-1-oxo-9-octadecenyl]amino]- sodium salt), and combinations thereof in an amount in the range from 1 to 10%.
Wetting is the first stage of dispersion, in which the air surrounding the granular composition is substituted with water. Wetting of the fungicidal composition with water cannot occur if the surface tension of the liquid is very high. Hence, it is recommended to add a wetting agent to the fungicidal composition to facilitate the process of dispersion of the granules in the liquid. Accordingly, the composition of the present invention preferably contains a wetting agent such as sodium lauryl sulfate or a sodium alkyl naphthalene sulfonate blend in an amount in the range from 2 to 3%.
A defoamer is usually added to a fungicidal composition, as foaming prevents effective utilization of the tank in which said composition is diluted with water. Hence, the fungicidal composition preferably contains dimethyl polysiloxane emulsion as a defoamer in an amount in the range from 0.01 to 0.50%.
The disintegration and dissolution of the water dispersible granules (WG or WDG) can be further improved by adding effervescent components, i.e., citric acid (an acid) and sodium bicarbonate (an alkali). Hence, these components are preferably present in an amount in the range from 0.10-5.00%.
A filler is yet another important component of fungicidal compositions, which improves handling and storage characteristics of said composition. Fillers also add mass and/or volume to the active ingredient in order to facilitate precise measurement of the doses. Suitable carriers that can be used in the present invention include, but not limited to, ammonium sulfate, silica, china clay and so forth.
The synergistic fungicidal composition of the present invention was found to be non-phytotoxic and has good stability, wettability, suspensibility and dispersibility.
It has been surprisingly found that the synergistic fungicidal composition of the present invention provides a wide spectrum control of fungal pathogens, delaying the appearance of the resistant strains of fungi, and achieving effective and economical control of undesired fungi.
The present invention is more particularly described in the following examples that are intented as illustrations only, since numerous modifications and variations within the scope of the present invention will be apparent to those of skill in the art. Unless otherwise noted, all parts, percentages, and ratios reported in the following examples are on a weight basis and all reagent used in the example were obtained or are available from the chemical suppliers.
EXAMPLES
The following examples illustrate embodiments of the proposed invention that are presently best known. However, other embodiments can be practiced that are also within the scope of the present invention. All of the agrochemical formulations, according to the scope of the present invention and exemplified below had excellent storage stability properties.
Examples 1 to 3:
The unit of each value below is “% w/w” i. e. the percentage by weight, relative to the weight of the total solution or composition unless otherwise specified. The compositions illustrated in Table 1 are formulated as water dispersible granules (WG).
Table 1: Synergistic fungicidal compositions
Component Function Examples (%)
1 2 3
Chlorothalonil A.I. 35.00 40.00 35.00
Thiophanate Methyl A.I. 35.00 35.00 30.00
Sodium Salt Of Naphthalene Sulfonate Condensate Dispersing Agent 7.00 8.00 6.00
Sodium Lauryl Sulphate Wetting Agent 2.00 3.00 2.00
Dimethyl Polysiloxane Anti-foaming Agent 0.02 0.02 0.02
Citric acid Disintegration agent 2.00 2.00 2.00
Sodium Bicarbonate 3.00 3.00 3.00
China Clay Filler q.s. q.s. q.s.
A.I.= active ingredient
q.s.= quantity suffucient
The aforementioned synergistic fungicidal compositions can be formulated as water dispersible granules (WG) by the process described below.

Process for preparing synergistic fungicidal composition in the form of water dispersible granules (WG):
The novel fungicidal compositions of examples 1 to 3 are prepared by the process described hereinafter. The process for manufacture of 100 kg batch size of fungicidal compositions comprising Chlorothalonil and Thiophanate Methyl is provided.
All the raw materials were verified for conformance to the laid down individual specifications. The raw materials required for preparing compositions of examples 1, 2 and 3 are illustrated in table 2 under the column headings 1, 2 and 3 respectively. Entries for Chlorothionil, and Thiophanate methyl in table 2 differ from those in table 1 as entries in table 1 are for 100% pure compounds, whereas those in table 2 are for technical ones, i.e. those containing a certain percentage of impurities.
The amounts of active ingredients presented in table 2 may be greater than the values calculated taking into account the percentage purity of the active ingredients, to compensate for losses of said ingredients during the manufacturing process. It was observed that following said procedure on industrial scale the final yield of A.I. will be similar or same as to standardized values.
Process 1: Process for preparing Water Dispersible Granules (WG) for a synergistic fungicidal composition comprising Chlorothalonil and Thiophanate methyl using spray dryer technique
Take wetting agent, dispersing agent and water and mix homogeneously in a high share mixing vessel and then add Chlorothalonil technical, Thiophanate methyl technical and other raw materials in the given proportion (table 2) and mix homogeneously.
The above mass is ground by bead mill. Grinding is carried out until a mean particle size of below 5 microns is obtained. After grinding, mix the homogeneous mass.
Spray dry the homogeneous mass through nozzle of the spray drying equipment to obtain the granules of 200 to 500 microns. Finally, dry the granules in a fluid bed dryer (FBD); and pack the dried granules.
Process 2: Process for preparing Water Dispersible Granules (WG) of a synergistic fungicidal composition comprising Chlorothalonil and Thiophanate methyl using extruder technique.
Take all the raw materials such as wetting agent, dispersing agent, defoamer or anti-foaming agent, fillers and technical grade active ingredients in the given proportion (table 2) and mix homogeneously by a blender.
The above homogenous mixture is ground by jet mill until a mean particle size of less than 10 microns is obtained.
After grinding, mix homogeneous mass by a blender, then prepare dough by dough mixer and thereafter prepare granules by an extruder. Finally, dry the granules in a fluid bed dryer (FBD); and pack the dried granules.

Table 2: Quantities of the *TGAI and raw materials charged
Component Function Weight in kg
1 2 3
Chlorothalonil @ 96% w/w *TGAI 36.46 41.67 36.46
Thiophanate Methyl @ 95% w/w *TGAI 36.85 36.85 31.58
Sodium Salt Of Naphthalene Sulfonate Condensate Dispersing Agent 7.00 8.00 6.00
Sodium Lauryl Sulphate Wetting Agent 2.00 3.00 2.00
Dimethyl Polysiloxane Anti-foaming Agent 0.02 0.02 0.02
Citric acid Disintegration agent 2.00 2.00 2.00
Sodium Bicarbonate 3.00 3.00 3.00
China Clay Filler 12.67 5.46 18.94
*Technical grade active ingredient
Evaluation of bio-efficacy of synergistic fungicidal composition against fungal diseases in tomato crop
In the evaluation of the synergistic effect, field trials were conducted on tomato to evaluate the fungicidal control of diseases such as early blight (Alternaria solani), late blight (Phytophthora infestans) and Anthracnose (Colletotrichum spp.) with Chlorothalonil and Thiophanate methyl alone and in binary mixture as a foliar application and also the vigor/yield of the plant was tested. The tomato crop was sown in field and harvested after 135 days. Experimental design was in randomized blocks with five replication and each plot was measured an area of 36 sq. m (6 m × 6 m). The binary mixture is prepared by the process described above. Commercially available compositions of Chlorothalonil (WILLONYL 75% WP) and Thiophanate methyl (THEME 70% WP) were diluted with water to the stated concentration of the active compound. Applications were made with a backpack type sprayer fitted with a pressure regulator and a vertical bar with one hollow cone nozzle. The rate of application was 200 L/acre for all the trials. Total of three applications were made at an interval of 14 days. The disease intensity rating (table 3) for different diseases was analysed at 7 and 14 days after each spray and their mean is calculated for each spray. Per cent disease index (PDI) was calculated by using formula adopted by Horsfall and Heuberger, 1942 ( Horsfall. J.G and J.W. Henberger. 1942. Measuring magnitude of defoliation disease of tomatoes. Phytopath., 32: 226-232) as follows:
The per cent disease index (PDI) was calculated by using the following formula:

Table 3: Scale for measurement of disease intensity rating
Grade Disease symptoms
0 No plants showing disease symptoms
1 1% or less plants showing disease symptoms
3 1-10% or less plants showing disease symptoms
5 11-20% or less plants showing disease symptoms
7 21-50% or less plants showing disease symptoms
9 51% and above plants showing disease symptoms
Table 4 below summarizes the individual and combined treatments for disease spectrum at different concentrations of Chlorothalonil and Thiophanate methyl.
Table 4: Treatment details for evaluation of bio-efficacy of fungicidal composition in tomato crop
Particulars Treatment A.I. Percentage Dose (a.i g/acre) Volume of formulation (g/mL)
T1 Chlorothalonil + Thiophanate methyl (1:1) 35 + 35 210 + 210 600
T2 Chlorothalonil + Thiophanate methyl (8:7) 40 + 35 240 + 210 600
T3 Chlorothalonil + Thiophanate methyl (7:6) 35 + 30 210 + 180 600
T4 Chlorothalonil 75% WP 75 375 500
T5 Thiophanate methyl 70% WP 70 200 286
T6 Untreated Control - - -
The bio-efficacy of different spray schedule on tomato plant and the treatment wise yield data of tomato fruits are summarized in the Table 5 and Table 6 below.

Table 5: Effectiveness of fungicidal treatments on disease spectrum in tomato crop demonstrating the synergistic effect of novel fungicidal composition of Chlorothalonil and Thiophanate methyl
Treatments details Volume (mL) PDI (%) Early Blight
(Alternaria solani) PDI (%) late Blight
(Phytophthora infestans) PDI (%) Anthracnose
(Colletotrichum spp.)
Mean after 1st spray Mean after 2nd spray Mean after 3rd spray Mean after 1st spray Mean after 2nd spray Mean after 3rd spray Mean after 1st spray Mean after 2nd spray Mean after 3rd spray
T1 600 3.01
(9.99) 3.54
(10.84) 4.01
(11.55) 1.63
(7.34) 1.73
(7.56) 1.79
(7.69) 1.12
(6.07) 1.68
(7.45) 1.96
(8.05)
T2 600 4.23
(11.87) 4.96
(12.87) 5.51
(13.58) 2.12
(8.37) 2.36
(8.84) 2.56
(9.21) 2.02
(8.17) 2.64
(9.35) 2.79
(9.62)
T3 600 6.63
(14.92) 8.91
(17.37) 10.69
(19.08) 5.39
(13.42) 7.09
(15.44) 8.87
(17.33) 4.69
(12.51) 5.89
(14.05) 6.64
(14.93)
T4 500 14.85
(22.67) 19.45
(26.17) 22.56
(28.36) 8.91
(17.37) 12.01
(20.28) 14.49
(22.37) 7.99
(16.42) 9.41
(17.86) 11.25
(19.60)
T5 286 17.79
(24.95) 20.46
(26.89) 24.19
(29.46) 10.01
(18.44) 13.12
(21.24) 15.64
(23.30) 8.16
(16.60) 10.02
(18.45) 11.85
(20.14)
T6 - 46.45
(42.96) 58.49
(49.89) 66.79
(54.81) 19.14
(25.94) 24.96
(29.97) 28.49
(32.26) 17.45
(24.69) 20.79
(27.13) 25.10
(30.07)
CD @ 5% - 0.85 1.05 1.03 0.95 1.13 1.12 0.06 0.08 0.24
SEm ± - 2.55 3.15 3.09 2.85 3.39 3.36 0.17 0.22 0.72
Values in parenthesis are arc sine transformed
SEm ±: Standard Errors of Means; CD 5%: Critical Difference

Table 6: Treatment wise yield of tomato fruits
Treatment Yield (q/ ha)
T1 (Chlorothalonil 35% + Thiophanate Methyl 35% WG) 279
T2 266
T3 260
T4 245
T5 240
T6 185
SEm ± 13.2
CD 5% 39.60
*SEm ±: Standard Errors of Means; CD 5%: Critical Difference; q/ha = quintal/hectare
From the data presented in tables 5 and 6 it is evident that application of Chlorothalonil 35% + Thiophanate Methyl 35% WG @ 600 g/acre showed good control of all the target disease along with higher yield in comparison to other ratios and market formulations. Further it was also observed that the novel fungicide composition also produced bolder fruits with better shine.
Evaluation of Phytotoxicity
Visual observations on phytotoxicity were recorded for leaf injury on tip/surface, Epinasty/Hyponasty, and wilting, etc. on 0 to10 scale (table 7) at 3, 7 and 14 days after each application from ten plants and the average values are presented in table 8.

Table 7: Phytotoxicity visual scoring 0-10
Score Phytotoxicity (percent)
0 No phytotoxicity
1 1 – 10
2 11 – 20
3 21 – 30
4 31 – 40
5 41 – 50
6 51 – 60
7 61 – 70
8 71 – 80
9 & 10 Complete destruction

Table 8: Phytotoxic effect of different treatments on the tomato crop.
Treatment Volume of formulation (mL) 1st Application 2nd Application 3rd Application
DAA DAA DAA
3 7 14 3 7 14 3 7 14
T1 600 0 0 0 0 0 0 0 0 0
T2 600 0 0 0 0 0 0 0 0 0
T3 600 0 0 0 0 0 0 0 0 0
T4 500 0 0 0 0 0 0 0 0 0
T5 286 0 0 0 0 0 0 0 0 0
T6 - 0 0 0 0 0 0 0 0 0
DAA = Days after application
It is clear from table 8 that no phytotoxicity was observed with any of the treatments at all the doses when observed at 3, 7, and 14 DAA (days after application) after each application.
From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present investigation. It is to be understood that no limitations with respect to the specific embodiment illustrated is intended or should be inferred. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims.

CLAIMS:
We claim:
1. A synergistic fungicidal composition, comprising Chlorothalonil, Thiophanate methyl and additives.
2. The synergistic fungicidal composition, as claimed in claim 1, wherein Chlorothalonil and Thiophanate methyl are present in a mass ratio in the range from 0.75:1 to 1.33:1, preferably 1:1.
3. The synergistic fungicidal composition, as claimed in claims 1 and 2, wherein Chlorothalonil is present in an amount in the range from 30 to 40% and Thiophanate methyl is present in an amount in the range from 30 to 40%.
4. The synergistic fungicidal composition, as claimed in claims 1 to 3, wherein the composition is in the form of a wettable powder (WP), a dry flowable (DF), a wettable solid (WS), a water dispersible granule (WG), or a suspension concentrate (SC).
5. The synergistic fungicidal composition, as claimed in claims 1 to 4, wherein the additives are selected from the group consisting of a dispersing agent, a wetting agent, a defoamer or an anti-foaming agent, a disintegration agent, a filler and combinations thereof, and wherein the composition is in the form of a water dispersible granule (WG).
6. The synergistic fungicidal composition as claimed in claim 5, wherein the dispersing agent is selected from the group consisting of sodium salt of naphthalene sulfonate condensate; sulfonated aromatic polymer sodium salt; sodium polycarboxylate; ethanesulfonic acid(2-[methyl[(9Z)-1-oxo-9-octadecenyl]amino]- sodium salt), and combinations thereof; and present in an amount in the range from 1 to 10%.
7. The synergistic fungicidal composition as claimed in claim 5, wherein the wetting agent is selected from the group consisting of sodium lauryl sulphate, sodium alkyl naphthalene sulfonate and combinations thereof, and present in an amount in the range from 2 to 3%.
8. The synergistic fungicidal composition as claimed in claim 5, wherein the defoamer or anti-foaming agent is preferably dimethyl polysiloxane emulsion and present in an amount in the range from 0.01 to 0.50%.
9. The synergistic fungicidal composition as claimed in claim 5, wherein the disintegration agent is preferably a mixture of citric acid and sodium bicarbonate, and present in an amount in the range from 0.10-5.00%.
10. The synergistic fungicidal composition as claimed in claim 5, wherein the filler is selected from the group consisting of ammonium sulphate, china clay, silica and combinations thereof.
11. The synergistic fungicidal composition, as claimed in any of the claims 1 to 10, wherein the composition is non-phytotoxic and has good stability, wettability, suspensibility and dispersibility.